one chime for each victim of the tragedy that struck newtown, connecticut, one week ago. yet even as this nation comes together to mourn, we remain deeply divided. all weeknight line has dedicated our broadcast to examining the complex relationship between america and its guns. tonight the most divisive day yet. here's my coanchor, terry moran. >> reporter: in newtown this morning, silence, one week after the children screaming and the madman shooting. sigh length across the country. silence in the oval office. and that ancient marker of mourning and remembrance, church bells. [ bells tolling ] >> reporter: the pain is still raw, the horror still fresh. but in washington the debate is already beginning and today a key voice, a powerful voice was at last heard. >> the national rifle association. >> reporter: wayne lapierre, the long-time executive vice president of the nra, took to the podium in washington just an hour or so after the national moment of remembrance. for a week, the nra had been silent, uncharacteristically silent as their opponents lambasted them. >> chang